1. Field of the Invention
The present invention relates to an operation state detecting apparatus which detects an operating state such as strength and speed of operation, an operation state detecting sheet, and an electronic instrument.
2. Description of the Related Art
Conventionally, there is a well-known application program in which an image simulating an acoustic instrument is displayed on a display of a portable terminal device, etc. provided with a touch panel and a user touches the touch panel to enable the user to play an imitation instrument.
When such program is used, even if the user does not own a drum set, the user can easily enjoy playing drums using the portable terminal apparatus.
However, although by using such touch panel provided in the electronic device such as a normal portable terminal apparatus, etc. it is possible to detect whether the touch panel is touched and the touched position on the touch panel, it is not possible to detect the strength and the speed that the touch panel is hit (pressed). Therefore, the sound output is the same regardless of how the touch panel is hit, and it is not possible to obtain the feel of playing an acoustic instrument (such as a drum) in which the degree of the sound changes depending on how hard and fast the instrument is hit.
Moreover, such touch panel does not have an uneven surface. Therefore, when an imitation instrument is played, the user needs to play the instrument while confirming the position to be touched on the display by sight. From this point also, the feel of playing the instrument is different from the acoustic instrument which can be played by confirming with the hands the position of the instrument and the position to be hit without looking.
Regarding this point, Japanese Patent Application Laid-Open Publication No. 2012-37856 discloses an operation input apparatus of an electronic percussion instrument which is provided with a plurality of elastic hitting pads on a membrane sheet and which is configured to play sound material associated to each hitting pad when the user hits the hitting pad.
According to such technique, a touch panel and a detecting circuit are provided for the electronic percussion instrument in advance. Therefore, the change in the contact square area of the electrode which changes according to the strength of the hit applied to the hitting pad can be detected as the strength of the hit, and output can be performed according to the above.